xquery version "1.0"; (: : Copyright 2006-2009 The FLWOR Foundation. : : Licensed under the Apache License, Version 2.0 (the "License"); : you may not use this file except in compliance with the License. : You may obtain a copy of the License at : : http://www.apache.org/licenses/LICENSE-2.0 : : Unless required by applicable law or agreed to in writing, software : distributed under the License is distributed on an "AS IS" BASIS, : WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. : See the License for the specific language governing permissions and : limitations under the License. :) (:~ : The module provides functions to compute an immutable and opaque reference : for any node and to retrieve nodes given their identifier. The identifiers : are immutable, i.e. a node identifier does not change during the node lifetime : and cannot be reused for another node after the original node gets deleted. : Identifiers are unique, in that, two different nodes will never have the same : identifier. A node, at any time during its lifetime, can be retrieved by its : identifier. : : <p>Please see the <a href="../../html/data_lifecycle.html">data lifecycle : documentation</a> about details on storing nodes in collections or as documents.</p> : : @see <a href="../../html/data_lifecycle.html">Data Lifecycle</a> : : @author Federico Cavalieri : : @project XDM/node : :) module namespace ref = "http://www.zorba-xquery.com/modules/node-reference"; declare namespace zerr = "http://www.zorba-xquery.com/errors"; declare namespace ver = "http://www.zorba-xquery.com/options/versioning"; declare option ver:module-version "2.0"; (:~ : Returns an immutable and opaque node reference (with type xs:anyURI) for : a given node. : : <p>The generated identifier is immutable, i.e. a node identifier does not : change during the node lifetime and cannot be reused for another node after : the original node gets deleted.</p> : : <p>Identifiers are also unique, in that, two different nodes will never : have the same identifier.</p> : : A node, at any time during its lifetime, can be retrieved by its : identifier, using the <tt>ref:node-by-reference</tt> function. : : @param $arg the node for which the URI should be computed : : @return the opaque URI of the node. :) declare function ref:node-reference( $arg as node() ) as xs:anyURI external; (:~ : Returns the node identified by the given node reference. : : <p>The function returns the empty sequence if the node : that is referenced does not exist.</p> : : @param $arg the URI of the node to retrieve. : : @return the node identified by the URI passed as parameter : or the empty-sequence if no node with that URI is found. : : @error zerr:ZAPI0028 if the given URI is not a valid node reference : computed by the <tt>ref:node-reference</tt> function. :) declare function ref:node-by-reference( $arg as xs:anyURI ) as node()? external;